Humphrey is a decent back-up caliber TE. He's remained on the squad since just prior to the playoffs last year.
I'm more concerned about Shockey in the long-term. He can't seem to stay healthy, and he's definitely lost a step or two. Nonetheless, he's still a quality TE ... but time is catching up with him. Graham is obviously whom the coaches consider the future starter at TE.
Shockey may not have lost a big a step as we think, did you see why he was limited in practice earlier this week, it was a tweaked groin that will make anyone lose a step. He might have had it for a while